Unit pixel having light emitting device and displaying apparatus

Abstract

A unit pixel includes a transparent substrate, a plurality of light emitting devices arranged on the transparent substrate, connection layers electrically connected to the light emitting devices, and bonding pads disposed over the connection layers and electrically connected to the connection layers. The bonding pads are partially overlapped with at least one of the light emitting devices in a vertical direction, respectively.

What is claimed is: 
     
       1. A unit pixel, comprising:
 a transparent substrate; 
 a plurality of light emitting devices arranged on the transparent substrate; 
 a plurality of connection layers electrically connected to the plurality of light emitting devices such that each light emitting device is electrically connected to each corresponding connection layer and a common connection layer of the plurality of connection layers; and 
 a plurality of bonding pads disposed over the plurality of connection layers, and electrically connected to the plurality of connection layers; 
 a light blocking layer disposed on the transparent substrate; 
 an adhesive layer disposed on the transparent substrate and configured to cover a region of the light blocking layer; and 
 a surface layer disposed between the transparent substrate and the light blocking layer, 
 wherein: 
 the light blocking layer has windows through which light generated from the plurality of light emitting devices passes, and 
 the plurality of light emitting devices are disposed to correspond to the windows. 
 
     
     
       2. The unit pixel of  claim 1 ,
 wherein the plurality of bonding pads further comprises a first bonding pad that is partially overlapped with two of the plurality of light emitting devices. 
 
     
     
       3. The unit pixel of  claim 1 ,
 wherein the transparent substrate has a concave-convex pattern on a surface facing the plurality of light emitting devices. 
 
     
     
       4. The unit pixel of  claim 1 ,
 wherein each of the plurality of light emitting devices has a first concave-convex pattern on a surface facing the transparent substrate and a second concave-convex pattern formed on the first concave-convex pattern. 
 
     
     
       5. The unit pixel of  claim 1 , wherein:
 the plurality of light emitting devices includes at least three light emitting devices emitting light of different colors, and 
 the at least three light emitting devices are arranged in a line. 
 
     
     
       6. A unit pixel, comprising:
 a transparent substrate; 
 a plurality of light emitting devices arranged on the transparent substrate; 
 a plurality of connection layers electrically connected to the plurality of light emitting devices such that each light emitting device is electrically connected to each corresponding connection layer and a common connection layer of the plurality of connection layers; and 
 a plurality of bonding pads disposed over the plurality of connection layers, and electrically connected to the plurality of connection layers; 
 a light blocking layer disposed on the transparent substrate; 
 a surface layer disposed between the light blocking layer and the transparent substrate; and 
 a patterned surface region disposed on the surface layer, 
 wherein: 
 the light blocking layer has windows through which light generated from the plurality of light emitting devices passes, and 
 the patterned surface region is disposed to correspond to the windows. 
 
     
     
       7. The unit pixel of  claim 6 , further comprising:
 a step adjustment layer covering the plurality of light emitting devices, 
 wherein: 
 the step adjustment layer has openings exposing the plurality of light emitting devices, and 
 the plurality of connection layers is disposed on the step adjustment layer and electrically connected to the plurality of light emitting devices through the openings of the step adjustment layer. 
 
     
     
       8. The unit pixel of  claim 7 , further comprising:
 an insulation material layer covering the plurality of connection layers, 
 wherein: 
 the insulation material layer has openings exposing the plurality of connection layers, and 
 the plurality of bonding pads is electrically connected to the plurality of connection layers through the openings of the insulation material layer. 
 
     
     
       9. The unit pixel of  claim 8 ,
 wherein the insulation material layer covers side surfaces of the step adjustment layer along with side surfaces of the plurality of connection layers. 
 
     
     
       10. The unit pixel of  claim 9 ,
 wherein the insulation material layer has a thickness smaller than a thickness of the step adjustment layer. 
 
     
     
       11. The unit pixel of  claim 9 ,
 wherein the step adjustment layer and the insulation material layer are formed of polyimide. 
 
     
     
       12. The unit pixel of  claim 7 , wherein:
 each of the plurality of light emitting devices includes:
 a light emitting structure including a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer interposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer; and 
 a first electrode pad and a second electrode pad disposed on the light emitting structure, wherein the openings of the step adjustment layer expose the first electrode pad and the second electrode pad. 
 
 
     
     
       13. The unit pixel of  claim 12 , wherein:
 each of the plurality of light emitting devices further includes: 
 an insulation layer disposed between the light emitting structure and the first electrode pad and the second electrode pad, 
 wherein the insulation layer includes a distributed Bragg reflector. 
 
     
     
       14. The unit pixel of  claim 13 , wherein:
 the plurality of light emitting devices includes a red light emitting device, a green light emitting device, and a blue light emitting device, and 
 an insulation layer of the blue light emitting device has a lower reflectance than a reflectance of an insulation layer of the red light emitting device and a reflectance of an insulation layer of a green light emitting device. 
 
     
     
       15. The unit pixel of  claim 1 ,
 wherein the transparent substrate has an area of 300 μm×300 μm or less. 
 
     
     
       16. A displaying apparatus, comprising:
 a circuit board having pads; 
 a plurality of unit pixels disposed on the circuit board; and 
 bonding materials configured to bond the plurality of unit pixels to the pads, 
 each of the plurality of unit pixels including: 
 a transparent substrate; 
 a plurality of light emitting devices arranged on the transparent substrate; 
 a plurality of connection layers electrically connected to the plurality of light emitting devices such that each light emitting device is electrically connected to each corresponding connection layer and a common connection layer of the plurality of connection layers; 
 a plurality of bonding pads disposed over the plurality of connection layers, and electrically connected to the plurality of connection layers; 
 a light blocking layer disposed on the transparent substrate; 
 a surface layer disposed between the transparent substrate and the light blocking layer; and 
 a patterned surface region disposed on the surface layer, 
 wherein the light blocking layer has windows through which light generated from the plurality of light emitting devices passes, and 
 wherein the patterned surface region is disposed to correspond to the windows. 
 
     
     
       17. The displaying apparatus of  claim 16 ,
 wherein the bonding materials include solder. 
 
     
     
       18. The displaying apparatus of  claim 16 , wherein:
 the plurality of light emitting devices is disposed to correspond to the windows. 
 
     
     
       19. The displaying apparatus of  claim 16 ,
 wherein the transparent substrate has an area of 300 μm×300 μm or less.